Interest of screening asymptomatic older adults for SARS-CoV-2 in nursing homes

Sourdeau, Elise; Cantin, Delphine; Meritet, Jean-François; Salmon, Dominique; Ravault, Etienne; Viard, Jean-Paul; Slama, Laurence

Importance: Since the beginning of the pandemic, COVID-19 affected specifically elderly people aged 70 years and over in whom the mortality rate is high. We may underestimate asymptomatic people or persons with atypical COVID-19 symptoms who may spread the disease. Objective: A large screening campaign was launched all over France in several retirement homes in order to screen asymptomatic persons for SARS-CoV-2 to isolate carriers from other residents. Methods: From April 24th to 27th 2020, mobile teams of nurses from the Hôtel-Dieu Hospital were sent to five Parisian nursing homes to conduct SARS-CoV-2 RT-PCR screening tests among all asymptomatic. Results: This cross-sectional study included 297 residents: 274 asymptomatic participants (92.3%) were tested for COVID-19, mostly women (n=249/274), median age was 90 (IQR 95% [86-94]) with females being significantly older than males (90 versus 88 years, p= 0.028). A total of 35 residents (12.8%) were tested positive for COVID-19: 29 women (11.7%) and six men (24%). The proportion of PCR-positive residents was extremely variable between retirement homes and analysis of COVID-19 positive cases dispersion in each nursing home showed there was no area cluster. Conclusion: There is a real public health interest in tracking SARS-CoV-2 positive asymptomatic elderly people in nursing homes.